Kling 4.0: 30-second clips with sound for six cents a second

Answer: Kling 4.0 on Callirra renders 3 to 30 second clips at 720p or 1080p, in text-to-video, image-to-video (including ordered keyframes) and video-to-video modes, with an audio track generated alongside the picture. At 720p it costs 6 credits per output second — $0.06 — and 8.9 credits ($0.089) at 1080p. An active Starter subscription or higher is required.

That combination is unusual in one specific way: thirty seconds, with sound, at six cents a second. Most models in this price bracket top out at five or ten seconds, and most of those deliver silent video that needs a separate audio pass.

What it is

What a clip costs

Those are settlement prices at one credit = $0.01. On higher plans the credit price falls, so the same clip costs less: at the top plan's yearly rate a thirty-second 720p take lands near $1.19.

The three modes, briefly

Text to video. Describe the action, the camera and the sound; choose duration, aspect and resolution. This is the mode the thirty-second ceiling matters most in, because a single take at that length is a scene rather than a reaction shot.

Image to video. One frame to establish the look, or two ordered keyframes to fix the start and the end of the move. The published examples use @first_frame and @last_frame to hold architecture steady across a ten-second dolly.

Video to video. Feed a clip as the reference and restyle or re-light it while keeping the route and motion — the example re-renders a coastal pavilion at blue hour from a daytime source.

Why sound changes the workflow

Because the audio arrives with the picture, a ten-second shot can be finished in one job instead of three: no separate ambience pass, no lining up footsteps afterwards. The prompt has to say what to hear, in the same breath as what to see — "begin with rain, quick mechanical footsteps and the low hum of the train; end on the small click of the lunchbox latch" is a real published example, and it is how you get a cut that reads as finished.

The catch is that you cannot fix the mix by pulling a stem. Once the clip is generated, the soundscape is baked into the file; changes mean a re-render.

Where it sits next to the other Kling models

Kling 4.0 being cheaper than 3.0 at 720p is the part that surprises people. It is not a downgrade — it is the current generation priced lower than the previous one.

When it is the wrong tool

• You need 4K. Kling 4.0 stops at 1080p; use Seedance 2.0 for 4K video.
• You need a frame-accurate silent plate for a VFX pipeline. A baked audio track is not a clean plate.
• You are below Starter. All Kling 4.0 modes require an active subscription.

FAQ

Does Kling 4.0 really make 30 seconds in one job? Yes — 3 to 30 seconds in one-second steps, priced per output second.

Is the audio separate from the video? No. It is generated with the clip; you direct it through the prompt.

Can I get a silent version? You can write "no music, no dialogue, room tone only" into the prompt, but you cannot pull a silent stem from a rendered file.

Is Kling 4.0 available without a subscription? No. Starter or higher.

The current per-second table is on Callirra's Kling 4.0 page, and the audio direction examples are worth reading before the first render.